<!DOCTYPE html>
<html class="reftest-wait">
<head>
<style>
  .outer { text-decoration: underline; }
  .inner {
    vertical-align: 1em;
    text-shadow: 0 1em green;
  }
  .reftest-wait .inner {
    text-shadow: 0 1em red;
  }
</style>
</head>
<body>
  <span class="outer"><span class="inner">x</span></span>
  <script>
    document.addEventListener("MozReftestInvalidate", () => {
      document.documentElement.removeAttribute('class');
    }, false);
  </script>
</body>
</html>
